Build 10C531 lists “MacBook Pro 6,1” and “MacBook Pro 6,2”, an indication of major revisions of the MacBook Pro lineup. The current family of MacBook Pro’s range from 5,1 to 5,5.

Last week’s introduction of refreshed iMacs brought Intel’s new Core i5 and i7 (Nehalem) processors to Apple’s most popular desktop machines, but the refreshed product lineup didn’t include any new MacBook Pros. Applesana suggests that the new MacBook Pro models will likely feature quad core processors based on Intel’s Arrandale architecture which brings i5/i7 technology to a more power-efficient mobile chip.

The last time Apple refreshed the MacBook Pro line was in early June at the Worldwide Developers Conference.

Hefty Update

10.6.2 is a significant update to Snow Leopard, bringing a raft of bug fixes and performance improvements to existing functionality. Nothing has been said about new features, however, the user guide for Apple’s new Magic Mouse makes the following reference to Mac OS X 10.6.2:

To use your Apple Magic Mouse and its full range of features, update your Mac to Mac OS X version 10.5.8 or later and install the Wireless Mouse Software Update 1.0; or update to Mac OS X version 10.6.2 or later.

Apple’s developers have been working hard. For those keeping count, this is 10.6.2’s fourth developer build in less than a month. The first, 10C514f, was seeded on Oct. 5. Only four days later, on Oct. 9, Apple produced build 10C519f. Developers were treated to build 10C527f just one week after that. And finally, 10C531 brings us to today.

At nearly 500MB, 10.6.2 is a hefty update, addressing an equally hefty assortment of bugs and issues affecting Snow Leopard. Most notably, this update is expected to fix a serious bug that can result in users losing all their personal data. MacRumor’s Doctor Q lists other fixes.

There is no indication yet as to when 10.6.2 will be released, though the speed at which these builds are being developed — and the urgent need for that data-wiping bug fix — mean we probably won’t be waiting much longer.